High-speed machines for shaping metals which employ the energy of high-pressure gas

ABSTRACT

A metal forming machine is disclosed having a working tool mounted on the head of a ram located within a receiver and performing a working stroke under the action of the compressed gas filling the receiver. In order to return the working tool to its initial position, the ram is connected through a rod with a crank gear. The rod through its one end is hinged to the crank arm and through its other end is connected to a piston which is located in the space provided within the ram. The stroke of the piston is somewhat greater than the stroke of the ram.

United States Patent [191 Morgolenko et al.

[ HIGH-SPEED MACHINES FOR SHAPING METALS WHICH EMPLOY THE ENERGY OF HIGH-PRESSURE GAS [22] Filed: Feb. 23, 1972 [21] App]. No.: 228,714

[11] 3,783,672 Jan. 8, 1974 [56] References Cited UNITED STATES PATENTS 3,427,851 2/1969 Michelson 72/408 3,623,352 11/1971 Kramer 72/453 FOREIGN PATENTS OR APPLICATIONS 89,438 5/ 1921 Switzerland 72/432 Primary ExaminerCharles W. Lanham Assistant Examiner-Gene P. Crosby Azt0rneyHolman & Stem 5 7] ABSTRACT A metal forming machine is disclosed having a working tool mounted on the head of a ram located within a receiver and performing a working stroke under the action of the compressed gas filling the receiver. In order to return the working tool to its initial position, the ram is connected through a rod with a crank gear. The rod through its one end is hinged to the crank arm and through its other end is connected to a piston [22] (SI. 72l40l'a7iil2l7tgg which is located in the Space provided within the ram. d 432 The stroke of the piston is somewhat greater than the le 0 earc ,l00/2,69 R, stroke of the ram.

3 Claims, 7 Drawing Figures 9 I9 I l5 7 l3 l4 4 4 4 A I 5/ r A 9 5 7 L l 20 PAIENTED 81974 SHEET 1 [If 3 PATENTED 81974 SHEET 2 0F 3 PATENTEB 4 SHEU 3 BF 3 BACKGROUND OF THE INVENTION The present invention relates to pressure shaping of metals and, more particularly, the invention relates to high-speed machines for shaping metals which employ the energy of high-pressure gas for accelerating the working tool to high speeds and operate in a closed thermodynamic cycle, i.e., without exhausting the gas into the atmosphere.

The machine accomplished according to the present invention is preferably used for accurate stamping of forged pieces having high thin with small tapers or without them (such as impellers of centrifugal pumps, etc.).

In the art it is known to have high-speed machines for pressure-shaping of metals in which'the working tool is accelerated to a high speed, and the energy stored by the moving members of the machine is expended for forming a blank.

The tool is accelerated by a high-pressure gas pumped into a receiver accomodating rams capable of moving towards each other and carrying heads mounting the working tools. The receiver is mounted on a stationary frame. Mounted on the same frame is a threecrank crankshaft the extreme cranks of which are connected to the head of one ram while the medium crank is coupled through a connecting rod with the head of the other ram.

The extreme cranks of the crankshaft are spaced at an angle of 180 relative to the medium crank. Mounted on one end of the crankshaft is an overrunning clutch connected with a drive for returning the plungers with the heads and working tools to the initial position (cf. U.S. Pat-No. 3,427,851, cl.72-408).

In the above-described machine the crankshaft is disposed under one of the heads so that the operating zone is clogged with the crank arms connected to the other head. Due to such a location of the crank arms the access to the operating zone of the machine is possible only at two sides and this hinders the arrangements of automatic control devices within this zone. Therefore, the high efficiency of the machine cannot be completely utilized due to limited facilities provided to the operating personnel.

Furthermore, when the rams with the heads and working tools return to their initial position, the longer crank arms of one of the heads are subject to compression and this necessitates an increase in their cross section, i.e., their weight, so as to provide for adequate mechanical strength in the arms. The increase in the weight of the crank arms results in a decrease in the efficiency of the machine since the arms are coupled to the heads and take part in the process of acceleration of the heads, Le, a portion of the energy of the highpressure gas is wasted. This occurs owing to the fact that the energy stored by the crank arms is not expended for shaping the blank, therefore, the arms should be as light as possible to reduce the, deleterious effect of high inertia forces appearing in the bottom dead centre and acting on the crankshaft.

Owing to the location of the crankshaft under one of the'heads this head is moved by means of at least two rams disposed within the receiver and provided with pistons which increase the amount of required sealing devices owing to the fact that, in addition to the rams, their pistons must be sealed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a machine wherein the operating zone may be used for mounting components of an automatic control system thereby making it possible to utilize the high efficiency of the crank gear returning the rams with the heads to the initial position.

Another object of the invention is to reduce the amount of sealing devices provided in the receiver.

Still another object of the invention is reduce the loads on the crankshaft due to the inertia forces of the weight of the crank arm appearing at the bottom dead centre.

According to these and other objects a high-speed metal forming machine is proposed in which at least one of the opposed working tools is mounted on the head of a ram capable of moving within a receiver and performing a working stroke under the action of the compressed gas filling the receiver and is kinematicaly connected with a drive for returning it to the initial position through a crank gear and an overrunning clutch, wherein according to the invention the ram is coupled to the crank arm through a rod one end of which terminates with a piston while the ram has an inner space on the side opposite to the mounting place of the working tool, which space accomodates said piston of the rod having its other end hinged to the crank arm, in which case the stroke of the piston is somewhat greater than the stroke of the ram.

In a bilateral-blow machine of the above-mentioned type both working tools are preferably equipped with separate rams which through connecting rods are coupled to the corresponding crank gears kinematically connected to each other for moving the working tools simultaneously from a single drive.

The kinematic connection of the crank gears is preferably effected through a chain drive having a driving sprocket mounted on an overrunning clutch which, in turn, in mounted on the crankshaft of one gear, and a driven sprocket mounted on the crankshaft of the other gear.

Such a kinematic connection is simple and is convenient for servicing.

If the machine is employed for briquetting loose material, it must be equipped with two containers with openings for charging the loose material, which containers are mounted in theguides of the frame opposite to each other and each container is provided with a head carrying a working too] capable of performing translatory motion. In this case each container can move in the axial direction, because it is connected through a cam mechanism to the corresponding crank gear for closing and opening the containers.

The high-speed metal forming machine according to the present invention makes it possible to make the most of the operating zone for arrangement of devices for automation and mechanization, in which case the efficiency of the machine is considerably increased. In addition, the proposed machine is simple in manufacture and is convenient and reliable in operation.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will be apparent from the description of some embodiments thereof taken in connection with the accompanying drawings, in which:

FIG. 1 illustrates a general view, partly in section, of a high-speed metal forming machine, according to the invention with a single movable working tool (singleblow machine);

FIG. 2 is the same with two movable working tools (bilateral-blow machine);

FIG. 3 is the same with containers for briquetting loose material;

FIGS. 4, 5, 6, 7 show the position of the containers relative to each other and relative to the working tools.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The high-speed metal forming machine has a frame 1 (FIG. 1) on which there is rigidly secured a working tool 2. A blank 3 to be deformed is placed on the tool 2. Mounted on the frame 1 is a receiver 4 filled with high-pressure gas. A ram 5 is installed within the receiver 4 opposite to the working tool 2 so that the longitudinal axis a of the ram 5 is a continuation of the longitudinal axis of the working tool 2. The ram 5 terminates with a head 6 carrying a second working tool 7. The energy of compressed gas is converted into the kinetic energy of the translatory motion of the ram 5 with a head 6 expended for deforming the blank 3 by the tools 2 and 7. Mounted on the frame 1 above the receiver 4 is a crank gear 8 which consists of a singlecrank crankshaft 9 mounted in bearings 10 and a crank arm 11. The crank gear 8 is mounted on the frame 1 on the side of the receiver opposite to the location of the working tool.

The above-said crank gear and the ram 5 are interconnected through a rod 12. One end of the rod 12 is hinged to the crank arm 11 providing the possibility of angular displacement. The other end of the rod 12 terminates with a piston 13. The latter is disposed within the space 14 of the ram 5.

The crank gear 8 serves for returning the ram 5 to the initial position after the working stroke performed by the ram under the action of compressed gas.

Such a connection of the crank gear 8 with the ram 5 makes it possible to create a machine with a free operating zone for accomodating therein devices for automatic control of the machine (not shown), and this allows the efficiency of the machine to be increased so that its manufacturing cost will be compensated within a shorter period of time.

Since the rod 12 is disposed within the receiver 4 filled with high-pressure gas, the inertia forces acting on the crank gear 8 when it passes the bottom dead centre are reduced due to the action of the gas pressure on the area of the rod 12, therefore, on selecting this area with due regard for the inertia loads encountered, it is possible to completely remove these loads from the gear 8. The disposition of the crank gear 8 on the side opposite to the disposition of the working tool 7 makes it possible to create a machine in which the arm 11 and rod 12 are subjected only to the tension loads, therefore, the weight of these components can be minimized as well as to use high-strength materials (wire ropes, hardened belts, etc.) for making these members.

The proposed machine has a small number of packing devices, namely for the ram 5 and rod 12, which fact increases the reliability of the machine and simplifies its servicing and repair.

The stroke of the piston 13 is selected to be somewhat greater than the stroke of the ram 5, and this makes it possible to eliminate the transmission of impact loads to the crank gear 8 and to dispose the blank 3 at that portion of the path of the ram 5 with the head 6 and tool 7 where their velocity is maximum, therefore, the energy stored by the head 6 and the ram 5 is also maximum.

Mounted on the frame 1 is a drive 15 employed for rotating the crank gear 8. The drive 15 consists of an electric motor 16, a reduction gear 17, a unilateral clutch 18 and an overrunning clutch 19. The reduction gear 17 increases the torque of the electric motor 16 and decreases the rotational speed on the output shaft of the reduction gear. The unilateral clutch l8 enables the crankshaft 9 to be stopped at a required moment when returning the ram 5 to the initial position without stopping the motor 16. The overrunning clutch 19 makes it possible to disengage the crankshaft 9 from the output shaft of the reduction gear 18 when the crank gear 8 attains the upper dead centre. This allows the ram 5 to perform a working stroke at a high speed under the action of the energy of the expanding gas, while the output shaft of the reduction gear 18 continues rotating at a constant speed.

Mounted on the frame 1 is a stop 20 which makes it possible to fix the ram with the head 6 in a predetermined position needed for safe servicing of the machine.

If the high-speed machine is made as a bilateral-blow device, i.e., when both working tools 21 (FIG. 2) and 22 are mounted with a possibility of movement towards each other at equal speeds, the machine is provided with two receivers 24 and 25 secured on the frame 23. These receivers are mounted so that the longitudinal axis b of one of the receivers is a continuation of the longitudinal axis of the other receiver. The receivers 24 and 25 have rams 26 and 27 carrying heads 28 and 29, respectively, with tools 21 and 22 mounted thereon.

Mounted on the frame 23 behind the receivers 24 and 25 at the side opposite to the location of the working tools 21 and 22 are crank gears 30 and 31, each consisting of a single-crank crankshaft 32 (33) and an arm 34 (35). The said cranks gears 30 and 31 and the rams 26 and 27 are connected through rods 36 and 37. One end of the rods 36 and 37 is hinged to the arm 34 (35) with a possibility of angular displacement. The other end of each rod 36 and 37 terminates with a piston 38 (39) which is located in the space 40 (41) provided in the rams 26 and 27. Similarly to the unilateralblow machine, the crank gears are used for returning the rams 26 and 27 to their initial position after they have performed the working stroke.

The frame 23 is provided with a drive 42 for rotating the crank gears 30 and 31. The drive 42 consists of an electric motor 43, a reduction gear 44, a unilateral clutch 45 and an overrunning clutch 46 which are used for the same purpose as in the above-described unilateral-blow machine.

The crank gears 30 and 31 are kinematically interconnected through a chain drive 47. Such a connection ensures simultaneous movement of the rams 26 and 27 during their return and acceleration. The driving sprocket of the chain drive 47 is arranged on the collar of the overrunning clutch 46 while the driven sprocket 48 is disposed on the axle of the crankshaft 33. Such arrangement of the crank gears 30 and 31 allows the movement of the working tools 21, 22 to be synchronized.

The chain drive can be replaced by a pinion drive, for which purpose it is sufficient to make the collar of the overrunning clutch and the driven sprocket in the form of pinions coupled through a system of intermediate gear wheels. Such a construction is expedient when producing machines of extremely high power.

Mounted on the frame 23 is a stop 49 whose function is the same as that in the single-blow machine.

A blank 50 to be shaped is secured in pincers 51 between the working tools 21 and 22 along the transverse axis of the machine.

, When using the high-speed machine for briquetting loose material, both working tools or punches 52, 53 (FIG. 3) are also driven towards each other at equal speeds. The machine also has two similar stationary receivers 54, 55 filled with compressed gas and mounted on the frame 56 symmetrically relative to the transverse axis C of the machine. Arranged within the receivers 54 and 55 are rams 57 and 58 with heads 59 and 60 carrying punches 52, 53. Mounted on the frame 56 in bearings 61 are crank gears 62 and 63, each of which consists repectively of a single-crank crankshaft 64 (65) and an arm 66 (67). The crank gears 62, 63 and rams 57, 58 are interconnected through rods 68, 69. The rods have one end hinged to the arm 66 (67) with a possibility of angular displacement. The other end of each rod 68, 69 terminateswith a piston 70 (71). The pistons 70, 71 are disposed within the spaces 72, 73 provided in the rams 57, 58. The heads 59, 60 move in containers 74, 75 mounted on the guides of the frame 56. These containers have openings 76, 77 for loading loose material 78 and are mounted in the guides of the frame 56 opposite to each other. Mounted onthe axles of the crankshafts 64, 65 are cam mechanisms 79, 80 which are rigidly connected with the containers 74, 75 through rods 81, 82. Each cam mechanism 79, 80 has a body 83 in which there is'placed a cam 84 mounted on the axle of the crankshaft 64 (65) and the rollers 85, 86 of the forward and return stroke respectively.

Mounted on the frame 56 is a drive 87 for rotating the crank gears 62, 63. This drive is made similarly to the drive 42.

The crank gears 62, 63 are kinematically coupled through a chain drive 88 similar to the chain drive 47 of the above-described bilateral-blow machine. The connection of the containers 74, 75 through cam mechanisms 79, 80 with the crank gears 62, 63 makes it possible to predetermine the mutual displacement of the containers 74, 75 and of the heads 59, 60 with the "punches 52, 53 providing for removing the obtained briquette from the containers 74, 75.

The frame 56 is provided with a stop 89 whose function is similar to that of the stop of the above-described machines with unilateral and bilateral blows.

The high-speed metal forming machine with a single movable working tool operates as follows.

In FIG. 1 the machine is shown in a position preceding the working stroke, i.e., blow of the blank 3 placed on the tool 2. The torque from the driving link electric motor 16 through a reduction gear 17, unilateral clutch 18 and the overrunning clutch 19 is transmitted to the crank gear 8. As soon as the crankshaft passes the upper dead centre, the driven links, i.e., the crankshaft 9, the crank arm 11 and the rod 12 with the ram 5 are automatically disengaged from the driving link electric motor 16, because the overrunning clutch automatically overruns. The ram 5 with the head 6 and the working tool 7 secured to the head 6 moves under the action of the expanding gas and through the piston 13 runs the rod 12, the arm 11 and the crankshaft 9, whereas the output shaft of the reduction gear 17 and the shaft of the electric motor 16 continue rotating at a constant speed due to the automatic disconnection of the overrunning clutch 19. The energy of the highpressure gas is transformed into the kinematic energy of translatory motion of the plunger 5 with the head 6 expended for deforming the blank 3. The blank 3 is installed on the working tool 2 within the zone of the highest speed of the head 6 owing to the fact that the stroke of the ram 5 with the head 6 is less than the stroke of the rod 12. When the ram 5 is stopped, the piston 13 of the rod 12 moves downwards to the bottom dead centre and, after passing this centre, ascends with acceleration both under the action of the energy stored by the crankshaft 9 and under the effect of the compressed gas acting on the rod 12 in the receiver 4. The piston 13 of the rod 12 rises up to the upper portion of the ram 5 and at this moment the overrunning clutch automatically comes into operation since the output shaft of the reduction gear continues rotating at a constant speed. The ram 5, while moving upwards, ensures additional compression of the gas in thereceiver 4. When the crank gear 8 attains the upper dead centre, the operating cycle is repeated. Thus, the machine operates automatically. For making single working strokes and for stopping the machine it is sufficient to simultaneously disconnect the unilateral clutch 18 and to put forward the stop 20 before the crank gear 8 approaches the position of the upper dead centre. In this case the crank gear 8 will slowly be disengaged from the drive 15. The ram 5 acted on by the gas pressure starts moving downwards together with the head 6 but the stop 20 will arrest the motion. In this position various auxiliary operations (placing a new blank 3, adjustment and replacement of the tools 2 and 7, etc.) are carried out within the operating zone.

For making the next blow it is necessary to put on the unilateral clutch 18 and to remove the stop 20, thereby the crank gear 8 starts rising to the upper dead centre and on reaching it, the process of acceleration of the ram 5 with the head 6 will be repeated. The output capacity of the machine, i.e., the amount of the blows applied to the blank 3, can be altered during the automatic operation of the machine, for example, at the expense of changing the speed of the electric motor or due to changing the revolutions of the reduction gear. In both cases the output capacity of the machine can be controlled without stopping it. This makes it possi- -ble to build the machine into automatic production lines with a variable operating cycle which is often needed by the operating duty.

The high-speedmetal forming machine with a bilateral blow, i.e., when both working tools 21 and 22 are accelerated to equal speeds, operates similarlyto the above-described machine.

FIG. 2 shows the machine ready for making a working stroke. The bilateral blow on the blank 50 is effected owing to the fact that the simultaneous movement of the rams 26,27 with the heads 28, 29 carrying the working tools 21, 22 is provided by a chain drive 47 kinematically connecting two crank gears 30 and 31 mounted on the frame.

The simultaneous movement of the crank gears 30 and 31 is provided owing to the fact that the external collar of the overrunning clutch 46 is made in the form of a sprocket and is mounted on the axle of the crankshaft 32, while a sprocket 48 is mounted on the axle of the second cranshaft 33; both sprockets are interconnected through a chain drive 47.

The drive 42 of the machine operates similarly to the drive of the above-described machine.

The blank 50 is suspended from the pincers 51 within the operating zone of the machine between the two tools 21 and 22 along the transverse axis C" of the machine, and this eliminates the tranmission of the impact loads to the pincers 51. Since the blow is exerted on both sides of the blank 50 with equal power, the force of deformation is completely closed through the heads 28, 29 and the rams 26, 27 and is not transmitted to the foundation of the machine. This permits the machine to be installed in shops side-by-side with accurate equipment and even on second or third floors of buildings which is impossible in the case of a single-blow machine.

FIG. 3 illustrates a diagram of a high-speed machine adapted for briquetting loose material. The briquetting of the loose material 78 is effected by punches 52, 53 in containers 74, 75 which are rigidly connected through rods 81, 82 with cam mechanisms 79, 80. The process of briquetting the loose material 78 is effected as follows.

In FIG. 3 the machine is shown prior to the process of acceleration of the rams 57, 58 with heads 59, 60 carrying punches 52, 53. The crankshafts 64, 65 are at the upper dead centres, the containers 74, 75 are closed, the loose material 78 is charged into the spaces of the containers 74, 75. In FIG. 4 the containers 74, 75 and of the punches 52, 53 are shown diagrammatically in the initial position.

When the crank gears 62, 63 pass the upper dead centre, the rams 57, 58 with the heads 59, 60 carrying the punches 52, 53 are accelerated. The process of acceleration is performed similarly to the same process in the above-described machine with bilateral blow. The position of the containers 74, 75 and the of heads 59, 60 with the punches 52, 53 after the process of briquetting the loose material 78 is shown in FIG. 5. In this position the punches 52, 53 through the heads 59, 60 are pressed to the material being briquetted through the rams 57, 58 acted on by the high-pressure gas, while the containers 74 and 75 are closed. The crankshafts 64, 65 under the action of the stored kinetic energy and, when the overrunning clutch is automatically put into operation also under the action of the energy of the rotation drive 87 continue their rotation, therefore, the cam 84 also rotates. The cam 84 when turning, acts on the reverse-stroke roller 86 and transfers the body 83 of the cam mechanism 79 (80). The cam mechanisms 79, 80 through the rods 81, 82 move apart the containers 74 and 75 to free the briquette. The rams 57, 58 with the heads 59, 60 and the punches 52, 53 remain in place due to the difference in the strokes of the rods 68, 69 and the rams 57, 58 which are held by the high-pressure gas occupying the receivers 54, 55.

The position of the heads 59, 60 with the punches 52, 53 and of the containers 74, 75 corresponding to this stage of operation is shown in FIG. 6.

When the pistons 70, 71 reach the top of the spaces 72, 73 of the rams 57, 58, the latter start moving, be-

cause at this moment the overrunning clutch of the drive 87 is automatically put into operation. The cam mechanisms 79, 80 and, therefore, the containers 74, 75 remain immovable to the moment of releasing the briquettes as shown in FIG. 7. The briquette falls from the operating zone of the machine by gravity. After the briquette has been released, the cam 84, while turning, acts on the forward-stroke roller 85 and the cam mechanisms 79, through the rods 81, 82 close the containers 74, 75. A new portion of the loose material 78 to be briquetted is charged into the containers 74, 75 through the openings 76, 77. When the crank gears 62, 63 reach the upper dead centre, the operating cycle is completed and the machine is ready for performing the next operating cycle. The simultaneous movement of both rams 57, 58 is effected with the aid of a chain drive 88 similarly to the above-described high-speed machine with a bilateral blow. The making of the single strokes and the control of the output capacity of the machine is effected in the same manner.

The mounting of the cam mechanisms 79, 80 of the axles of the crankshafts 64, 65 and the rigid connection of these cam mechanisms with the containers 74, 75 through the rods 81, 82 make it possible to obtain briquettes having high density and strength of cuttings of conventional and hard metals and alloys as well as of other loose materials with high machine efficiency. Furthermore, the proposed machine has high technological characteristics and is very reliable and convenient in operation.

We claim:

1. A high-speed metal forming machine comprising in combination: a frame; a first working tool secured on said frame; a receiver means filled with compressed gas and mounted on said frame so that its longitudinal axis is a continuation of the longitudinal axis of said working tool; a ram placed into said receiver, said ram moving under the action of said compressed gas thereby performing a working stroke from an initial to a final position; a head located on said ram; a second working tool mounted on said head; a crank gear mounted on said frame at the side of said receiver means opposite to the location of said second working tool and comprising: a single-crank crankshaft and a crank arm; an overrunning clutch mounted on said crankshaft, a rod means connecting said crank gear and said ram, said rod means having its one end hinged to said crank arm and its other end connected to a piston; a space provided in said ram defining means for accommodating said piston and its working stroke, wherein said working stroke of said piston is greater than said working stroke of said ram; a drive mounted on said frame and connected through said overrunning clutch with said crank gear for returning said ram to said initial position.

2. A high-speed metal forming machine, wherein two working tools are mounted opposite to each other and reciprocate towards one another, said machine comprising: a frame; two receiver means filled with compressed gas and mounted on said frame so that the longitudinal axis of one of said receiver means is a continuation of the longitudinal axis of said other receiver means; two rams, each being located in a respective one of said receiver means; and means for moving said two rams towards each other under the action of said compressed gas thereby constraining said two rams to perform working strokes; two heads, each being arranged on a respective one of said two rams; working tools mounted on each of said heads; two crank gears mounted on said frame behind each one of said receiver means at the side opposite to the location of said working tools, each one of said two gears having a crankshaft and a crank arm; two rod means, one end of each one of said two rod means hingedly connected to said crank arm of each one of said two gears respectively, while the other ends of each one of said two rod means are connected to pistons; spaces provided within said two rams each one of said spaces defining means for accommodating each one of said pistons and their corresponding working strokes, wherein said stroke of each of said pistons is greater than said working stroke of each of said corresponding two rams; an overrunning clutch mounted on one of said crankshafts; a single drive means mounted on said frame and kinematically connected through said overrunning clutch to said crank gears for simultaneously operating said working tools from said single drive means.

3. A high-speed metal forming machine as claimed in claim 2, in which said kinematic connection is effected through a chain drive having driving and driven sprockets said driving sprocket being arranged on said overrunning clutch mounted on said crankshaft of one of said two crank gears and said driven sprocket being mounted on said crankshaft of the other one of said two crank gears. 

1. A high-speed metal forming machine comprising in combination: a frame; a first working tool secured on said frame; a receiver means filled with compressed gas and mounted on said frame so that its longitudinal axis is a continuation of the longitudinal axis of said working tool; a ram placed into said receiver, said ram moving under the action of said compressed gas thereby performing a working stroke from an initial to a final position; a head located on said ram; a second working tool mounted on said head; a crank gear mounted on said frame at the side of said receiver means opposite to the location of said second working tool and comprising: a single-crank crankshaft and a crank arm; an overrunning clutch mounted on said crankshaft, a rod means connecting said crank gear and said ram, said rod means having its one end hinged to said crank arm and its other end connected to a piston; a space provided in said ram defining means for accommodating said piston and its working stroke, wherein said working stroke of said piston is greater than said working stroke of said ram; a drive mounted on said frame and connected through said overrunning clutch with said crank gear for returning said ram to said initial position.
 2. A high-speed metal forming machine, wherein two working tools are mounted opposite to each other and reciprocate towarDs one another, said machine comprising: a frame; two receiver means filled with compressed gas and mounted on said frame so that the longitudinal axis of one of said receiver means is a continuation of the longitudinal axis of said other receiver means; two rams, each being located in a respective one of said receiver means; and means for moving said two rams towards each other under the action of said compressed gas thereby constraining said two rams to perform working strokes; two heads, each being arranged on a respective one of said two rams; working tools mounted on each of said heads; two crank gears mounted on said frame behind each one of said receiver means at the side opposite to the location of said working tools, each one of said two gears having a crankshaft and a crank arm; two rod means, one end of each one of said two rod means hingedly connected to said crank arm of each one of said two gears respectively, while the other ends of each one of said two rod means are connected to pistons; spaces provided within said two rams each one of said spaces defining means for accommodating each one of said pistons and their corresponding working strokes, wherein said stroke of each of said pistons is greater than said working stroke of each of said corresponding two rams; an overrunning clutch mounted on one of said crankshafts; a single drive means mounted on said frame and kinematically connected through said overrunning clutch to said crank gears for simultaneously operating said working tools from said single drive means.
 3. A high-speed metal forming machine as claimed in claim 2, in which said kinematic connection is effected through a chain drive having driving and driven sprockets said driving sprocket being arranged on said overrunning clutch mounted on said crankshaft of one of said two crank gears and said driven sprocket being mounted on said crankshaft of the other one of said two crank gears. 